Package encapsulant compositions for use in electronic devices

ABSTRACT

A curable composition for encapsulating an electronic component comprises one or more mono- or polyfunctional maleimide compounds, or one or more mono- or polyfunctional vinyl compounds other than maleimide compounds, or a combination of maleimide and vinyl compounds, with a free radical curing agent, and optionally, one or more fillers.

[0001] The priority of U.S. provisional application No. 60/091,493 isclaimed under 35 USC 119(e).

FIELD OF THE INVENTION

[0002] This invention relates to package encapsulant compositions forelectronic devices that protect the electronic component and itsmetallization from environmental corrosion and mechanical damage.

BACKGROUND OF THE INVENTION

[0003] Microelectronic devices contain millions of electrical circuitcomponents, mainly transistors assembled in integrated circuit (IC)chips, but also resistors, capacitors, and other components. Theintegrated circuit component may comprise a single bare chip, a singleencapsulated chip, or an encapsulated package of single or multi-chips.These electronic components are interconnected to form the circuits, andeventually are connected to and supported on a carrier or substrate,such as a printed wire board.

[0004] The various materials used to manufacture the integrated circuitsand their related interconnect materials are susceptible toenvironmental, moisture, and mechanical damage. Protection is providedby encapsulation of the electronic component within a polymericmaterial. Encapsulation can be performed by a transfer molding processin which the component is loaded into a mold cavity, constrained, andthe polymeric encapsulant transferred from a reservoir into the cavityunder pressure. Typically, the encapsulant is a thermosetting polymer,which then cross-links and cures to form the final assembly.Encapsulation also can be performed by dispensing an aliquot ofpolymeric encapsulant onto the component, such as a chip or integratedcircuit supported on a substrate, and subsequently curing thecomposition.

[0005] For most commercial and industrial end uses, particularly thoseutilizing chip-on-board packages and multi-chip modules, theencapsulation is accomplished with polymeric thermosetting materials.The preferred thermosetting package encapsulation materials must have aviscosity and a thixotropic index that allows easy dispensability bysyringe, sufficient adhesion to the components, low ionic content toavoid corrosion of the metallization, adequate mechanical strength, highthermal and moisture resistance at application temperatures, and matchedcoefficient of thermal expansion to the materials it contacts.

[0006] For single chip packaging involving high volume commodityproducts, a failed chip can be discarded without significant loss.However, it becomes expensive to discard multi-chip packages with onlyone failed chip, and the ability to rework the failed component would bea manufacturing advantage. Today, one of the primary thrusts within thesemiconductor industry is to develop not only a package encapsulant thatwill meet all the requirements for protection of the component, but alsoa package encapsulant that will be reworkable, allowing for the failedcomponent to be removed without destroying the substrate.

[0007] In order to achieve the required mechanical performance andreworkability, relatively high molecular weight thermoplastics would bethe preferred compositions for package materials. These materials,however, have high viscosity or even solid film form, which aredrawbacks to the manufacturing process. Therefore, there is a need fornew encapsulant compositions that are easily dispensable to conform withautomated manufacturing processes, and that are reworkable.

SUMMARY OF THE INVENTION

[0008] This invention is a curable encapsulant composition forelectronic components that comprises one or more compounds containingone or more maleimide functionality, or one or more compounds containingone or more vinyl functionality, or a combination of compoundscontaining maleimide or vinyl functionality, a free-radical initiatorand/or a photoinitiator, and optionally one or more fillers.

[0009] A compound containing one maleimide functionality will bereferred to hereinafter as a mono-functional maleimide compound. Acompound containing more than one maleimide functionality will bereferred to hereinafter as a poly-functional maleimide compound. Acompound containing one vinyl functionality will be referred tohereinafter as a mono-functional vinyl compound. A compound containingmore than one vinyl functionality will be referred to hereinafter as apoly-functional vinyl compound. The functionality is defined herein tobe a carbon to carbon double bond.

[0010] In another embodiment, this invention is also a cured encapsulantcomposition that results after the curing of the just described curableencapsulant composition.

[0011] In another embodiment, this invention is an electronic componentelectrically and mechanically connected to a substrate, encapsulated ina cured encapsulant composition, in which the cured encapsulant wasprepared from a composition comprising one or more mono- orpolyfunctional maleimide compounds, or one or more mono- orpolyfunctional vinyl compounds other than maleimide compounds, or acombination of maleimide and vinyl compounds, a free radical curingagent and/or a photoinitiator, and optionally one or more fillers.

DETAILED DESCRIPTION OF THE INVENTION

[0012] The maleimide and vinyl compounds used in the package encapsulantcompositions of this invention are curable compounds, meaning that theyare capable of polymerization, with or without crosslinking. As used inthis specification, to cure will mean to polymerize, with or withoutcrosslinking. Cross-linking, as is understood in the art, is theattachment of two polymer chains by bridges of an element, a moleculargroup, or a compound, and in general will take place upon heating. Ascross-linking density is increased, the properties of a material can bechanged from thermoplastic to thermosetting, which consequentlyincreases polymeric strength, heat-and electrical resistance, andresistance to solvents and other chemicals.

[0013] It is possible to prepare polymers of a wide range of cross-linkdensity, from tacky, elastomeric to tough glassy polymers, by thejudicious choice and amount of mono- or polyfunctional compounds. Thegreater proportion of polyfunctional compounds reacted, the greater thecross-link density.

[0014] If thermoplastic properties are desired, the package encapsulantsof this invention can be prepared from mono-functional compounds tolimit the cross-link density. However, a minor amount of poly-functionalcompounds can be added to provide some cross-linking and strength to thecomposition, provided the amount of poly-functional compounds is limitedto an amount that does not diminish the desired thermoplasticproperties. Within these parameters, the strength and elasticity ofindividual package encapsulants can be tailored to a particular end-useapplication. The cross-link density can also be controlled to give awide range of glass transition temperatures in the cured encapsulant towithstand subsequent processing and operation temperatures.

[0015] In those cases where it is necessary to rework the assembly, athermoplastic composition should be chosen so that the electroniccomponent can be pried off the substrate. Any residue packageencapsulant can be heated until it softens and then be easily removed.

[0016] In the inventive package encapsulant compositions, the maleimidecompounds and the vinyl compounds may be used independently, or incombination. The maleimide or vinyl compounds, or both, will be presentin the curable package encapsulant compositions in an amount from 2 to98 weight percent based on the organic components present (excluding anyfillers).

[0017] The package encapsulant compositions will further comprise atleast one free-radical initiator, which is defined to be a chemicalspecies that decomposes to a molecular fragment having one or moreunpaired electrons, highly reactive and usually short-lived, which iscapable of initiating a chemical reaction by means of a chain mechanism.The free-radical initiator will be present in an amount of 0.1 to 10percent, preferably 0.1 to 3.0 percent, by weight of the maleimide orvinyl compound, or a combination of both maleimide and vinyl compounds(excluding any filler). The free radical curing mechanism gives a fastcure and provides the composition with a long shelf life before cure.Preferred free-radical initiators include peroxides, such as butylperoctoates and dicumyl peroxide, and azo compounds, such as2,2′-azobis(2-methyl-propanenitrile) and2,2′-azobis(2-methyl-butanenitrile).

[0018] Alternatively, the encapsulant compositions may contain aphotoinitiator, such as is sold by Ciba Specialty Chemicals under thetrademark Irgacure, in lieu of the free-radical initiator, and thecuring process may then be initiated by UV radiation. The photoinitiatorwill be present in an amount of 0.1 to 10 percent, preferably 0.1 to 3.0percent, by weight of the maleimide or vinyl compound, or a combinationof both maleimide and vinyl compounds (excluding any filler). In somecases, both photoinitiation and free-radical initiation may bedesirable. For example, the curing process can be started by UVirradiation, and in a later processing step, curing can be completed bythe application of heat to accomplish a free-radical cure.

[0019] In general, these compositions will cure within a temperaturerange of 80° to 180° C., and curing will be effected within a length oftime of 5 minutes to 4 hours. As will be understood, the time andtemperature curing profile for each encapsulant composition will vary,and different compositions can be designed to provide the curing profilethat will be suited to the particular industrial manufacturing process.

[0020] Ease of application, even when thermoplastic properties aredesired for the package encapsulant, is achieved by using relatively lowmolecular weight reactive oligomers or pre-polymers and curing these insitu after application to the electronic assembly of component andsubstrate. Applying the materials in an uncured state gives highprocessibility, and the resultant cured thermoplastic encapsulantprovides high mechanical performance.

[0021] For some packaging operations, inert inorganic fillers are usedin the package encapsulant to adjust the coefficient of thermalexpansion to more closely mirror that of the circuit interconnect, andto mechanically reinforce the interconnect. Examples of suitablethermally conductive fillers include silica, graphite, aluminum nitride,silicon carbide, boron nitride, diamond dust, and clays. The fillerswill be present typically in an amount of 20-80 percent by weight of thetotal package encapsulant composition.

[0022] As used throughout this specification: the notation C(O) refersto a carbonyl group.

Maleimide Compounds

[0023] The maleimide compounds suitable for use in the packageencapsulant compositions of this invention have a structure representedby the formula:

[0024] [M—X_(m)]_(n)—Q, or by the formula: [M—Z_(m)]—K. For thesespecific formulae, when lower case “n” is the integer 1, the compoundwill be a mono-functional compound; and when lower case “n” is aninteger 2 to 6, the compound will be a poly-functional compound.

[0025] Formula [M—X_(m)]_(n)—Q represents those compounds in which:

[0026] M is a maleimide moiety having the structure

[0027] in which R¹ is H or C₁ to C₅ alkyl;

[0028] each X independently is an aromatic group selected from thearomatic groups having the structures (I) through (V):

[0029] and Q is a linear or branched chain alkyl, alkyloxy, alkyl amine,alkyl sulfide, alkylene, alkyleneoxy, alkylene amine, alkylene sulfide,aryl, aryloxy, or aryl sulfide species having up to about 100 atoms inthe chain, which may contain saturated or unsaturated cyclic orheterocyclic substituents pendant from the chain or as part of thebackbone in the chain, and in which any heteroatom present may or maynot be directly attached to X;

[0030] or Q is a urethane having the structure:

[0031] in which each R² independently is an alkyl, aryl, or arylalkylgroup having 1 to 18 carbon atoms; R³ is an alkyl or alkyloxy chainhaving up to 100 atoms in the chain, which chain may contain arylsubstituents; X is O, S, N, or P; and n is 0 to 50;

[0032] or Q is an ester having the structure:

[0033] in which R³ is an alkyl or alkyloxy chain having up to 100 atomsin the chain, which chain may contain aryl substituents:

[0034] or Q is a siloxane having the structure:

[0035] —(CR¹ ₂)_(e)—[SiR⁴—O]_(f)—SiR⁴ ₂—(CR¹ ₂)_(g)— in which the R¹substituent independently for each position is H or an alkyl grouphaving 1 to carbon atoms and the R⁴ substituent independently for eachposition is an alkyl group having 1 to 5 carbon atoms or an aryl group,and e and g are independently 1 to 10 and f is 1 to 50; and

[0036] m is 0 or 1, and n is 1 to 6.

[0037] Preferably, X is structure (II), (III), (IV) or (V), and morepreferably is structure (II).

[0038] Preferably, Q is a linear or branched chain alkyl, alkyloxy,alkylene, or alkyleneoxy species having up to about 100 atoms in thechain, as described with pendant saturated or unsaturated cyclic orheterocyclic substituents, or a siloxane as described, and morepreferably is a linear or branched chain alkyl species or siloxane, asdescribed.

[0039] Formula [M-Z_(m)]_(n)-K represents those compounds in which

[0040] M is a maleimide moiety having the structure

[0041] in which R¹ is H or C₁ to C₅ alkyl;

[0042] Z is a linear or branched chain alkyl, alkyloxy, alkyl amine,alkyl sulfide, alkylene, alkyleneoxy, alkylene amine, alkylene sulfide,aryl, aryloxy, or aryl sulfide species having up to about 100 atoms inthe chain, which may contain saturated or unsaturated cyclic orheterocyclic substituents pendant from the chain or as part of thebackbone in the chain, and in which any heteroatom present may or maynot be directly attached to K;

[0043] or Z is a urethane having the structure:

[0044] in which each R² independently is an alkyl, aryl, or arylalkylgroup having 1 to 18 carbon atoms; R³ is an alkyl or alkyloxy chainhaving up to 100 atoms in the chain, which chain may contain arylsubstituents; X is 0, S, N, or P; and n is 0 to 50;

[0045] or Z is an ester having the structure:

[0046] in which R³ is an alkyl or alkyloxy chain having up to 100 atomsin the chain, which chain may contain aryl substituents;

[0047] or Z is a siloxane having the structure:

[0048] —(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)—SiR⁴ ₂—(CR¹ ₂)_(g)— in which the R¹substituent independently for each position is H or an alkyl grouphaving 1 to 5 carbon atoms and the R⁴ substituent independently for eachposition is an alkyl group having 1 to 5 carbon atoms or an aryl group,and e and g are independently 1 to 10 and f is 1 to 50;

[0049] K is an aromatic group selected from the aromatic groups havingthe structures (VI) through (XIII) (although only one bond may be shownto represent connection to the aromatic group K, this will be deemed torepresent any number of additional bonds as described and defined by n):

[0050] in which p is 1 to 100;

[0051] in which p is 1 to 100;

[0052] in which R⁵, R⁶, and R⁷ are a linear or branched chain alkyl,alkyloxy, alkyl amine, alkyl sulfide, alkylene, alkyleneoxy, alkyleneamine, alkylene sulfide, aryl, aryloxy, or aryl sulfide species havingup to about 100 atoms in the chain, which may contain saturated orunsaturated cyclic or heterocyclic substituents pendant from the chainor as part of the backbone in the chain, and in which any heteroatompresent may or may not be directly attached to the aromatic ring; or R⁵,R⁶, and R⁷ are a siloxane having the structure —(CR¹ ₂)_(e)—[SiR⁴₂—O]_(f)—SiR⁴ ₂—(CH₃)_(g)— in which the R¹ substituent is H or an alkylgroup having 1 to 5 carbon atoms and the R⁴ substituent independentlyfor each position is an alkyl group having 1 to 5 carbon atoms or anaryl group, and e is 1 to 10 and f is 0 to 50;

[0053] and m is 0 or 1, and n is 1 to 6.

[0054] Preferably, Z is a linear or branched chain alkyl, alkyloxy,alkylene, or alkyleneoxy species having up to about 100 atoms in thechain, as described with pendant saturated or unsaturated cyclic orheterocyclic substituents, or a siloxane as described, and morepreferably is a linear or branched chain alkyl species or siloxane, asdescribed.

[0055] Preferably, K is structure (VIII), (X) or (XI), more preferablyis structure (X) or (XI), and most preferably is structure (X).

[0056] The more preferred maleimide compounds, particularly for use asreworkable encapsulants, are N-butylphenyl maleimide and N-ethylphenylmaleimide.

Vinyl Compounds

[0057] The vinyl compounds (other than the maleimides) herein will havethe structure:

[0058] For these specific structures, when lower case “n” is the integer1, the compound will be a mono-functional compound; and when lower case“n” is an integer 2 to 6, the compound will be a poly-functionalcompound.

[0059] In these structures, R¹ and R² are H or an alkyl having 1 to 5carbon atoms, or together form a 5 to 9 membered ring with the carbonsforming the vinyl group; B is C, S, N, O, C(O), O—C(O), C(O)—O, C(O)NHor C(O)N(R⁸), in which R⁸ is C₁ to C₅ alkyl; m is 0 or 1; n is 1-6; andX, Q, Z, and K are as described above.

[0060] Preferably, B is O, C(O), O—C(O), C(O)—O, C(O)NH or C(O)N(R⁸);more preferably B is O, C(O), O—C(O), C(O)—O, or C(O)N(R⁸).

Other Composition Components

[0061] Depending on the nature of the substrate to which the packageencapsulant is to be bonded, the encapsulant may also contain a couplingagent. A coupling agent as used herein is a chemical species containinga polymerizable functional group for reaction with the maleimide andother vinyl compound, and a functional group capable of condensing withmetal hydroxides present on the surface of the substrate. Such couplingagents and the preferred amounts for use in compositions for particularsubstrates are known in the art. Suitable coupling agents are silanes,silicate esters, metal acrylates or methacrylates, titanates, andcompounds containing a chelating ligand, such as phosphine, mercaptan,and acetoacetate. When present, coupling agents typically will be inamounts up to 10 percent by weight, and preferably in amounts of 0.1-3.0percent by weight, of the maleimide and other monofunctional vinylcompound.

[0062] In addition, the encapsulant compositions may contain compoundsthat lend additional flexibility and toughness to the resultant curedencapsulant. Such compounds may be any thermoset or thermoplasticmaterial having a Tg of 50° C. or less, and typically will be apolymeric material characterized by free rotation about the chemicalbonds, such as can be obtained by the presence of carbon-carbon doublebonds adjacent to carbon-carbon single bonds, the presence of ester andether groups, and the absence of ring structures. Suitable suchmodifiers include polyacrylates, poly(butadiene), polyTHF (polymerizedtetrahydrofuran), CTBN (carboxy-terminated butyronitrile) rubber, andpolypropylene glycol. When present, toughening compounds may be in anamount up to about 15 percent by weight of the maleimide and othermonofunctional vinyl compound.

[0063] If siloxane moieties are not part of the maleimide or vinylcompound structure, siloxanes can be added to the package encapsulantformulations to impart elastomeric properties. Suitable siloxanes arethe methacryloxypropyl-terminated polydimethyl siloxanes, and theaminopropyl-terminated polydimethylsiloxanes, available from UnitedChemical Technologies.

[0064] Other additives, such as adhesion promoters, may also be added asneeded. The kinds and amounts of adhesion promoters that may be used areknown to those skilled in the art.

[0065] Another embodiment of this invention includes the maleimideshaving the formulae [M—X _(m)]_(n)—Q and [M—Z _(m)]_(n)—K as describedherein in which Q and Z can be an ester having the structure

[0066] or the structure

[0067] in which p is 1 to 100,

[0068] each R³ can independently be an alkyl or alkyloxy chain having upto 100 atoms in the chain, which chain may contain aryl substituents, or

[0069] a siloxane having the structure —(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)—SiR⁴₂—(CR¹ ₂)_(g)— in which the R¹ substituent independently for eachposition is H or an alkyl group having 1 to 5 carbon atoms, the R⁴substituent independently for each position is an alkyl group having 1to 5 carbon atoms or an aryl group, e and g are independently I to 10and f is 1 to 50.

[0070] Another embodiment of this invention includes the vinyl compoundshaving the structures

[0071] as described herein in which B is C, S, N, O, C(O), C(O)NH orC(O)N(R⁸), in which R⁸ is C₁ to C₅ alkyl.

[0072] Another embodiment of this invention includes the vinyl compoundshaving the structures

[0073] as described herein in which Q and Z can be an ester having thestructure

[0074] or the structure

[0075] in which p is 1 to 100,

[0076] each R³ can independently be an alkyl or alkyloxy chain having upto 100 atoms in the chain, which chain may contain aryl substituents,

[0077] or a siloxane having the structure

[0078] —(CR¹ ₂)_(e)—[SiR¹ ₂—O]_(f)SiR⁴ ₂—(CR¹ ₂)_(g)— in which the R¹substituent independently for each position is H or an alkyl grouphaving 1 to 5 carbon atoms, the R⁴ substituent independently for eachposition is an alkyl group having 1 to 5 carbon atoms or an aryl group,e and g are independently 1 to 10, and f is 1 to 50.

[0079] Another embodiment of this invention includes the composition asdescribed herein containing an anionic or cationic curing initiator. Thetypes and useful amounts of such initiators are well known in the art.

EXAMPLES

[0080] Various maleimide and vinyl compounds were prepared andformulated into package encapsulant compositions. The compositions wereinvestigated for viscosity and thixotropic index for the uncuredcomposition, and for curing profile, glass transition temperature,coefficient of thermal expansion, thermal mechanical analysis, andreworkability for the cured composition.

Example 1 Preparation of Benzamido-encapped Dimer Diamine Bismaleimide

[0081]

[0082] Dimer diamine (sold as Versamine 552 by Henkel, 20.0 g, 37 mmol)was solvated in Et₂O (200 mL) in a 500 mL three-necked flask equippedwith an addition funnel, magnetic stirring, internal temperature probeand nitrogen inlet/outlet. NaOH_(aq) (11. 7 mL of 6.25 M solutiondiluted with 100 mL H₂O, 73 mmol) was added with vigorous stirring. Thissolution was placed under a steady flow of nitrogen and cooled to 3° C.on an ice bath with stirring. The addition funnel was charged withp-nitrobenzoyl chloride (13.6 g, 73 mmol) in iethyl ether (Et₂O) (50mL), and this solution was added to the reaction vessel over the courseof 60 minutes, maintaining an internal T<10° C.. The reaction wasstirred at ˜30C for an additional 60 minutes after this addition wascomplete, then allowed to warm to room temperature and stirred foranother 4 hours. The solution was transferred to a separatory funnel andthe isolated organic layer washed with distilled H₂O (300 mL), 5%HCl_(aq) (300 mL), NaCl_(aq) (250 mL) and distilled H₂O (2×250 mL). Theorganics were isolated, dried over MgSO₄ anhyd., filtered and thesolvent removed in vacuo to yield the dinitro compound as a viscousyellow oil which exhibited acceptable ¹H NMR and IR spectra (30.0 g,96%).

[0083] The dinitro compound described above (5.0 g, 5.9 mmol) wasdissolved in methanol (MeOH) (25 mL) and THF (5 mL) in a 250 mLthree-necked flask equipped with magnetic stirring, reflux condensor andnitrogen inlet/outlet. The solution was placed under nitrogen, and 5%Pd-C (0.96 g) were added with stirring. Ammonium formate (3.4 g, 55mmol) was added and the reaction stirred at room temperature for 2hours. Carbon dioxide evolution was immediately observed. The reactionsolution was filtered, and bulk filtrate solvent was removed via rotaryevaporator. The resulting viscous oil was dissolved in diethyl ether(Et₂O) (150 mL), washed with distilled H₂O (150 mL), isolated and driedover MgSO₄ anhyd. Solvent was removed in vacuo to yield the diamine as asticky tan oil, which exhibited acceptable ¹H NMR and IR spectra (3.9 g,84%).

[0084] Maleic anhydride (0.5 g, 5.1 mmol) was dissolved in acetone (10mL) in a 250 mL three-necked flask equipped with magnetic stirring,addition funnel and nitrogen inlet/outlet. The solution was cooled on anice bath and placed under nitrogen. The addition funnel was charged withan acetone (10 mL) solution of the diamine described above (2.0 g, 2.60mmol), which was added dropwise over 30 minutes. The reaction wasstirred for an additional 30 minutes on the ice bath, then allowed towarm to room temperature, and stirred for another 4 hours. To theresulting slurry was added acetic anhydride (Ac₂O) (1.54 mL, 160 mmol),triethyl amine (Et₃N) (0.23 mL, 1.63 mmol) and sodium acetate (NaOAc)(0.16 g, 1.9 mmol). The resulting slurry was heated to mild reflux for 5hours. The reaction was allowed to cool to room temperature, and solventremoved via rotary evaporator to yield a brown oil. This material wasdissolved in CH₂Cl₂ (250 mL) and washed with distilled H₂O (200 mL),satd. NaHCO₃ (200 mL) and distilled H₂O (200 mL). Emulsions were brokenby adding NaCl when necessary. The organic layer was isolated, driedover MgSO₄ anhyd. and solvent removed in vacuo to yield thebismaleimide, a brown solid (2.0 g, 83%). The resin exhibitedsatisfactory ¹H NMR, ¹³C NMR and IR spectra, which indicated slightcontamination with acetic acid.

Example 2 Preparation of 20-Bismaleimido-10,11-dioctyl-eicosame (andIsomers)

[0085]

[0086] In a 5 L multi-neck flask equipped with a drying tube,thermometer, slow addition funnel, mechanical stirrer and nitrogen purgemaleic anhydride (98.06 g, 1.02 equivalents on —NH₂) was dissolved in500 ml tetrahydrofuran (THF). Stirring was begun and the solution waschilled with a dry ice/water bath. Slow addition of dimer diamine(Versamine 552, Henkel, 245.03 g, 0.4477 mol) in 250 ml THF was begun.Addition was carried out over 1 hour. After addition was complete theice bath was removed and 375 ml of THF was rinsed through the slowaddition funnel to incorporate solidified diamine. After one hour theice bath was replaced around the flask. 1-Hydroxybenzotriazole (96.79 g,0.80 equivalents on —NH₂) was added rinsing into the flask with 50mlTHF. When the temperature had reached 5° C. slow addition ofdicyclohexylcarbodiimide (DCC) (188.43 g, 1.02 equivalents on —NH₂) in200 ml THF was begun. The temperature during addition was kept below tendegrees. After DCC addition was complete the slow addition funnel wasrinsed with 80 ml of THF. The ice bath was removed. The reaction wasmonitored by IR. When it appeared that the isoimide has been convertedto maleimide (approximately 4 hours after the completion of DCCaddition) the mixture was filtered, rinsing the solids with THF. Theorange solution was placed in the freezer overnight.

[0087] The solution was removed from the freezer and allowed to warm toroom temperature. Hydroquinone (0.0513 g) was added to the solution. Apartial strip of the THF was carried out on a rotary evaporator with thetemperature maintained below 28° C. The solution was concentrated toapproximately 800 ml. Much particulate matter was visible. The solutionwas placed in freezer overnight.

[0088] The mixture was removed from the freezer and allowed to warm. Thesolids were filtered, rinsing with THF. The filtrate was transferred toa 2 L multi-neck flask equipped with a mechanical stirrer, vacuum lineconnected to a trap, and a glass tube attached by tubing to a dryingtube. The remaining THF was stripped at room temperature by pulling avacuum and bubbling air through the material while stirring. Theresultant thick, creamy-tan colored semi-solid was placed in the freezerovernight.

[0089] The semi-solid was removed from the freezer and allowed to warm.The semi-solid was dissolved in 450 ml each of methanol and hexane, andwashed with 50% methanollwater (4×250 ml) to remove1-hydroxybenzotriazole (HOBT). It was attempted to extract the productwith hexane. After addition of 300 ml of hexane separation was notobserved. The mixture was washed with additional water (3×250 ml). Theorganic phase was placed in the freezer overnight.

[0090] The material was removed from the freezer. Two layers wereapparent. The upper layer was clear and yellow in color. The bottomlayer was a orange and cloudy. The material was poured cold into aseparatory funnel. The top layer was hexane and the desired product. Thebottom layer was extracted with hexane (6×200 ml), separation occurredeasily. The combined extracts were dried over anhydrous magnesiumsulfate and filtered, rinsing the solids with hexane. The solvent wasstripped to an approximate volume of 750 ml on a rotary evaporator withthe temperature not exceeding 24° C. The remaining solvent was strippedoff using a vacuum/air bubbling set-up at room temperature to give thedesired product in 67% yield.

Example 3 Preparation of Butadiene-Acrylonitrile Bismaleimide

[0091]

[0092] Amino-terminated butadiene-acrylonitrile (sold as Hycar resin1300×42 ATBN by BF Goodrich, in which the m and n depicted in thestructure are integers to provide a number average molecular weight of3600) (450 g, 500 mmol based on amine equivalent weight AEW=450 g) wasdissolved in CHCl₃ (1000 mL) in a 3 L four-necked flask equipped withaddition funnel, mechanical stirrer, internal temperature probe andnitrogen inlet/outlet. The stirred solution was placed under nitrogenand cooled on an ice bath. The addition funnel was charged with maleicanhydride (98.1 g, 1 mol) in CHCl₃ (50 mL) and this solution was addedto the reaction over 30 minutes, maintaining the internal reactiontemperature below 10° C. This mixture was stirred for 30 minutes on ice,then allowed to warm to room temperature and stirred for an additional4hours. To the resulting slurry was added acetic anhydride (Ac₂O) (653.4g, 6 mol), triethyl amine (Et₃N) (64.8 g, 0.64 mol) and NaOAc (62.3 g,0.76 mol). The reaction was heated to mild reflux for 5 hours, allowedto cool to room temperature, and subsequently extracted with H₂O (1 L),satd. NaHCO₃ (1 L) and H₂O (2×1 L). Solvent was removed in vacuo toyield the maleimide terminated butadiene acrylonitrile.

Example4 Preparation of Tris(maleimide) Derived FromTris(epoxypropyl)isocyanurate

[0093]

[0094] Tris(epoxypropyl)isocyanurate (99.0 g, 0.33 mol) is dissolved inTHF (500 mL) in a 2 L three-necked flask equipped with mechanicalstirrer, internal temperature probe and nitrogen inlet/outlet. To thissolution is added hyroxyphenylmaleimide (189.2 g, 1 mol) andbenzyldimethylamine (1.4 g, 0.05 wt. %). The solution is heated to 80°C. for 7 hours. The reaction is allowed to cool to room temperature, isfiltered, and the filtrant washed with 5 % HCl_(aq) (500 mL) anddistilled H₂O (1 L). The resulting solid, triazinetris-(maleimide), isvacuum dried at room temperature.

Example 5 Preparation of Maleimidoethylpalmitate

[0095]

[0096] Palmitoyl chloride (274.9 g, 1 mol) is dissolved in Et₂O (500 mL)in a 2 L three-necked flask equipped with mechanical stirrer, internaltemperature probe, addition funnel and nitrogen inlet/outlet. NaHCO₃(84.0 g, 1 mol) in distilled H₂O (500 mL) is added with vigorousstirring and the solution cooled on an ice bath under nitrogen. Theaddition funnel is charged with hydroxyethylmaleimide (141 g, 1 mol) inEt₂O (100 mL) and this solution added to the reaction over a period of30 minutes, maintaining an internal T<10° C. during the addition. Thereaction is stirred for another 30 minutes on ice, then allowed to warmto room temperature and stirred for 4 hours. The reaction is transferredto a separatory funnel and the isolated organic layer washed withdistilled H₂O (500 mL), 5% HCl_(aq) (500 mL) and distilled H₂O (2×500mL). The organics are isolated, dried over MgSO₄ anhyd., filtered andsolvent removed in vacuo to yield the aliphatic maleimide.

Example 6 Preparation of Bismaleimide Derived from5-Isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane

[0097]

[0098] 5-Isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane(111.15 g, 0.5 mol) is solvated in THF (500 mL) in a 1 L three-neckedflask equipped with mechanical stirrer, addition funnel and nitrogeninlet/outlet. The reaction is placed under nitrogen, and dibutyltindilaurate (cat. Sn^(ll)) (6.31g, 10 mmol) and hydroxyethylmaleimide (141g, 1 mol) are added with stirring, and the resulting mixture heated for4 hours at 70° C. The addition funnel is charged withhydroxyethylmaleimide (141 g, 1 mol) dissolved in TH F (100 mL). Thissolution is added to the isocyanate solution over 30 minutes, and theresulting mixture heated for an additional 4 hours at 70° C. Thereaction is allowed to cool to room temperature and solvent removed invacuo. The remaining oil is dissolved in CH₂C₂ (1 L) and washed with 10%HCl_(aq) (1 L) and distilled H₂O(2×1 L). The isolated organics are driedover MGSO₄, filtered and the solvent removed in vacuo to yield themaleimide.

Example 7 Preparation of Dimer Divinyl Ether Derived From Pripol 2033

[0099]

“Dimer Divinyl Ether” (and Cyclic Isomers)

[0100] Bis(1, 10-phenanthroline)Pd(OAc)₂ (0.21 g, 0.54 mmol) wasdissolved in a mixture of butyl vinyl ether (8.18 g, 81.7 mmols),heptane (100 mL) and “dimer diol” (sold as Pripol 2033 by Unichema, 15.4g, 27.2 mmol) in 2 L three-necked flask equipped with a mechanicalstirrer under nitrogen. This solution was heated to light reflux for 6h. The solution was allowed to cool to room temperature and subsequentlypoured onto activated carbon (20 g) and stirred for 1 hour. Theresulting slurry was filtered, and excess butyl vinyl ether and heptanewere removed in vacuo to yield the divinyl ether as a yellow oil. Theproduct exhibited acceptable ¹H NMR, FT-IR and ¹³C NMR spectralcharacteristics. Typical viscosity ˜100 cPs.

Example 8 Preparation of Dimer Diacrylate Derived From Dimer Diol(Pripol 2033)

[0101]

[0102] A dimer diol (sold as Pripol 2033 by Unichema, 284.4 g, 500 mmol)is dissolved in dry acetone (500 mL) in a 1 L three-necked flaskequipped with mechanical stirrer, addition funnel and internaltemperature probe under nitrogen. Triethylamine (101.2 g, 1 mol) isadded to this solution and the solution cooled to 4° C. on an ice bath.Acryloyl chloride (90.5 g, 1 mol) solvated in dry acetone (100 mL) ischarged into the addition funnel and added to the stirred reactionsolution over the course of 60 minutes, maintaining an internaltemperature <10° C. This solution is stirred on ice for an additional 2hours, then allowed to warm to room temperature and stirred for 4 hours.Bulk solvent is removed via a rotary evaporator, and the remainingresidue solvated in CH₂Cl₂ (1 L). This solution is washed with 5%HCl_(aq) (800 mL), and H₂O (2×800 mL). The isolated organics are driedover MgSO₄ anhyd. and filtered, and the solvent removed in vacuo toyield the diacrylate as an oil.

Example 9 Preparation of N-ethylphenyl Maleimide

[0103] 4-Ethyl aniline (12.12g) was dissolved in 50 ml of anhydrousethyl ether and slowly added to a stirred solution of 9.81 g of maleicanhydride in 100 ml of anhydrous ethyl ether chilled in an ice bath.After completion of the addition, the reaction mixture was stirred for30 minutes. The light yellow crystals were filtered and dried. Aceticanhydride (200 ml) was used to dissolve the maleamic acid and 20 g ofsodium acetate. The reaction mixture was heated in an oil bath at 160°C.. After 3 hours of reflux, the solution was cooled to roomtemperature, placed in a 1 L beaker in ice water and stirred vigorouslyfor 1 hour. The product was suction-filtered and recrystallized inhexane. The collected crystalline material was dried at 50° C. in avacuum oven overnight. FTIR and NMR analysis showed the characteristicsof ethyl maleimide.

Example 10 Preparation of Bis(alkenylsulfide)

[0104]

[0105] Dimer acid (sold under the trademark Empol 1024 by Unichema)(574.6 g, 1 mol) and propargyl alcohol (112.1 g, 2 mol) are solvated intoluene (1 L) in a 3 L three-necked flask equipped with mechanicalstirring and a Dean-Stark distillation apparatus. Concentrated H₂SO₄ (6mL) is added and the solution refluxed for 6 hours until 36 mL of H₂O isazeotropically distilled. The solution is allowed to cool to roomtemperature, is washed with H₂O (2×1 L), dried over MgSO₄ anhyd. and thesolvent removed in vacuo to yield the propargyl ester intermediate as anoil.

[0106] This ester intermediate (650.7 g, 1 mol) is solvated in THF (200mL) in a 1 L three-necked flask equipped with reflux condenser,mechanical stirrer and internal temperature probe under nitrogen. Laurylmercaptan (404.8 g, 2 mol) and 2,2′-azobis(2,4-dimethylpentanenitrile)(sold under the trademark Vazo 52 by DuPont) (11 g) are added and theresulting mixture heated to 70° C. on an oil bath with stirring for 7hours. The reaction is allowed to cool to room temperature and solventremoved in vacuo to yield the alkenyl sulfide as an oil.

Example 11 Package Encapsulant Compositions

[0107] Package encapsulant compositions were prepared by mixing togetherthe organic components and then by blending the components with a silicafiller in a weight percent ratio of 17% organic to 83% silica under highshear until homogeneous. The silica was FB-6S silica from Denka. Theresulting compositions were light yellow slurries. The organiccomponents, silica ratio by weight, glass transition temperature (Tg),and coefficient of thermal expansion (CTE) are reported here:Composition Sample 11-A Sample 11-B Sample 11-C Sample 11-D MaleimideN-4-butyl- N-4-ethyl- Dimer Bis- phenyl phenyl diamine maleimide*maleimide maleimide bismaleimide 1.0 g 22.9 g 20.1 g 1.0 g 82.0 wt %51.9 wt % 48.7 wt % 82.0 wt % Vinyl-t-butyl- 20.4 g 20.4 g 0.2 g 0.2 gbenzoate 46.2 wt % 49.4 wt % 16.4 wt % 16.4 wt % Dicumyl 0.45 g 0.40 g0.01 g 0.01 g peroxide 1.0 wt % 1.0 wt % 0.8 wt % 0.8 wt % Methacyloxy0.40 g 0.40 g 0.01 g 0.01 g trimethoxy- 0.9 wt % 1.0 wt % 0.8 wt % 0.8wt % silane Tg 140° C. 145° C. 42° C. 37° C. CTE 16 ppm/° C. 15 ppm/° C.16 ppm/° C. 15 ppm/° C.

Example 12 Reworkability

[0108] Each composition 11-A to 11-D was tested for reworkability usingas a test vehicle a 250×250 mil² silicon die bonded with the compositionto a FR-4 circuit board substrate. The encapsulant composition wasdispensed onto the chip adhered to the substrate and the assembly curedat 160° C. for 30 minutes. After the assembly again reached roomtemperature, a sponge was saturated with methyl isobutyl ketone and usedto wipe the encapsulant in a continuous, circular motion. Theencapsulant was gradually softened, and it dissolved within 10 minutessufficiently to leave no residue on the substrate.

[0109] This Example demonstrates that these compositions can be made tobe reworkable.

Example 13 UV and Thermally Curable Compositions

[0110] Composition 13-A

[0111] A package encapsulant composition was prepared by combining thefollowing ingredients with vigorous manual mixing until a homogenouspaste was obtained: Bismaleimide 1.01 g (prepared frompolytetramethylene oxide- di-ρ-aminobenzoate, sold as Versalink P-650 byHenkel) Cyclohexanedimethanol divinylether 0.19 g (InternationalSpecialty Products): α,α-Dimethoxy-a-phenylacetophenone 0.06 g (sold asIrgacure 651 by Ciba Specialty Chemicals) Hydrophilic Fused Silica 3.78g (sold by Denka, ˜5 micron)

[0112] A 250 mil×250 mil silicon die placed on FR-4 laminate wasencapsulated with the above paste and irradiated for 30 seconds using apulsed xenon UV source (RC-500B Pulsed UV Curing System, XenonCorporation). The encapsulant exhibited a hard, fully cured surface andheld the die firmly to the laminate material when force was applied. Thesample assembly was subsequently placed in a 175° C. oven for 20minutes. The encapsulated die was allowed to cool to room temperatureand then forcibly removed from the laminate. No regions of uncuredencapsulant were detected around the die edge, the laminate/adhesiveinterface or the adhesive/air surface interface.

[0113] Composition 13-B

[0114] A package encapsulant composition was prepared by combining thefollowing ingredients with vigorous manual mixing until a homogenouspaste was obtained: Bismaleimide 1.01 g (prepared frompolytetramethylene oxide- di-p-aminobenzoate, sold as Versalink P-650 byHenkel) Cyclohexanedimethanol divinylether 0.19 g (InternationalSpecialty Products): t-Butyl-2-ethylhexanoate 0.03 g Hydrophilic FusedSilica 3.78 g (sold by Denka, ˜5 micron)

[0115] A 250 mil×250 mil silicon die placed on FR4 laminate wasencapsulated with the above paste and placed in a 150° C. oven for 30min. The test assembly was allowed to cool to room temperature and thedie was forcibly removed from the laminate. No regions of uncuredencapsulant were detected around the die edge, the laminate/adhesiveinterface or the adhesive/air surface interface.

Example A Preparation of 6-maleimidocaproic Acid

[0116]

6-maleimidocaproic Acid

[0117] The acid functional maleimide, 6-maleimidocaproic acid, wassynthesized using known methodology.¹ Aminocaproic acid (100 g, 7.6×10⁻¹mols) was dissolved in glacial acetic acid (50 mL) in a 500 mLfour-necked flask equipped with mechanical stirring, an internaltemperature probe and an addition funnel. The addition funnel wascharged with a solution of maleic anhydride (74.8 g, 7.6×10⁻¹ mols)dissolved in acetonitrile (75 mL). This solution was added to theaminocaproic acid at room temperature dropwise over 1 hour, maintainingan internal reaction temperature less than 35° C. The reaction wasstirred for three hours after the addition was complete. The reactionslurry was filtered, and the isolated filtrate was dried in a vacuumoven (P˜25 T) overnight at 70° C. to yield 166 g of off white solid(95%). The product amic acid exhibited FT-IR and ¹H NMR spectralcharacteristics consistent with literature data.

[0118] The amic acid described above (166 g, 7.2×10⁻¹ mols) was solvatedin a solution of toluene (200 mL), benzene (200 mL) and triethylamine(211 mL, 1.51 mol) in a 1 L three-necked flask equipped with mechanicalstirring and a Dean-Stark trap under nitrogen. This solution was heatedto reflux for 4 h and the water produced collected in the Dean-Starktrap. Distilled water (400 mL) was added to the reaction flask todissolve the triethylammonium salt of the product which largelyseparated from the bulk solution during the reaction. This aqueous layerwas isolated, acidified to pH-1 with 50% HCl, and extracted with ethylacetate (600 mL). This organic layer was washed with distilled water(400 mL). The isolated organic layer was dried over MgSO₄, followed bysolvent removal in vacuo to yield an off white solid (76.2 g, 50%). Theproduct 6-maleimidocaproic acid was spectrographically identical toliterature material by FT-IR and ¹H NMR.

Example B Preparation of “Dimer Diester Bismaleimide”

[0119]

“Dimer Diester Bismaleimide” (and Cyclic Isomers)

[0120] Pripol 2033 (“dimer diol”, Uniqema, 92.4 g, 1.69×10⁻¹ mols),6-maleimidocaproic acid (75.0 g, 3.55×10⁻¹ mols) and H₂SO₄ (0.50 mL,˜8.5×10⁻³ mols) were slurried in toluene (300 mL) in a 1 L four-neckedflask equipped with mechanical stirrer, a Dean-Stark trap and aninternal temperature probe under nitrogen. The reaction was heated tolight reflux for two hours and the water evolved collected in theDean-Stark trap. The trap was drained and ˜50 mL of toluene solvent wasdistilled off of the reaction to remove trace moisture and drive theesterification equilibrium to completion. The reaction was allowed tocool to room temperature, additional toluene (100 mL) was added (on thelaboratory scale it is preferable to add diethyl ether in place oftoluene at this point), and the solution was washed with saturatedNaHCO₃ aq. (300 mL) and distilled water (300 mL). The organic layer wasisolated and dried over anhydrous MgSO₄, and the solvent removed invacuo to yield an orange oil (107.2 g, 68%). The material can be furtherpurified by eluting a toluene solution of the resin through a short plugof silica or alumina. This liquid bismaleimide resin exhibitedacceptable FT-IR, ¹H NMR, and ¹³C NMR data. Typical η˜2500 cPs.

Example C Preparation of “Decane Diol Diester Bismaleimde”

[0121]

“Decane Diol Diester Bismaleimide”

[0122] The general procedure described in Example B. was appliedsubstituting decane diol (29.5 g, 1.69×10⁻¹ mols) for Pripol 2033. Thisprocess yielded a solid, moderately soluble bismaleimide (54.9 g, 58%).The product exhibited satisfactory FT-IR and ¹H NMR data.

Example D Preparation of “Glycerol Triester Tris(maleimide)”

[0123]

[0124] The protocol outlined in example B. was utilized substitutingglycerol (10.4 g, 1.13×10⁻¹ mol) for Pripol 2033. The product was aviscous liquid which exhibited acceptable FT-IR and ¹H NMR data.

Example E Preparation of “Bis(m-nitrobenzyl carbamate) of IPDI”

[0125]

“Bis(m-nitrobenzyl carbamate) of IPDI”

[0126] Isophorone diisocyanate (“IPDI”, 100.0 g, 4.5×10⁻¹ mols),m-nitrobenzyl alcohol (137.8 g, 9.0×10⁻¹ mols) and dibutyl tin dilaurate(2.8 g, 4.5×10⁻³ mols) were solvated in dry toluene (1500 mL) in a 2 Lthree-necked flask equipped with mechanical stirrer, reflux condensorand internal temperature probe under nitrogen. The resulting solutionwas heated to 90° C. for 4 h. No isocyanate band was observed in the IRof the solids portion of the sample. The solution was allowed to cool toroom temperature and washed with distilled H₂O (100 mL). The organiclayer was isolated and solvent removed in vacuo to yield a yellow liquidwhich exhibited acceptable FT-IR and 1H NMR characteristics.

Example F Preparation of “Bis(m-aminobenzyl Carbamate) of IPDI”

[0127]

“Bis(m-aminobenzyl Carbamate) of IPDI”

[0128] The dinitro compound from Example E. (8.28 g, 1.57×10⁻² mols) wasdissolved in ethanol (100 mL) in a 500 mL three-necked round bottomflask equipped with magnetic stirring under nitrogen. Cyclohexene (28.6mL, 2.82×10⁻¹ mols) was added, followed by 5% Pd/C (4.14 g). Theresulting slurry was refluxed lightly for 6.5 h. The FT-IR of a filteredaliquot of this solution exhibited no nitro stretching bands at 1529cm⁻¹ and 1352 cm⁻¹. The bulk solution was allowed to cool to roomtemperature and filtered. Solvent was removed in vacuo to yield a yellowsemisolid (6.6 g, 90%) which exhibited acceptable FT-IR and ¹H NMRspectral characteristics.

Example G Preparation of “Bis(m-maleimidobenzyl Carbamate) of IPDI”

[0129]

“Bis(m-maleimidobenzyl Carbamate) of IPDI”

[0130] The diamine from Example F (6.6 g, 1.41×1⁻² mols) was solvated inacetone (60 mL) in a 250 mL four-necked flask equipped with magneticstirrer and addition funnel under nitrogen and cooled to 4° C. Maleicanhydride (2.76 g, 2.82×10⁻² mols) dissloved in acetone (20 mL) wasadded over the course of 30 minutes. The resulting solution was stirredat 4° C. for 1 h, and subsequently was allowed to warm to roomtemperature and stirred overnight. FT-IR analysis indicated no maleicanhydride remained as judged by the absence of the anhydride stretchingband at ˜1810 cm⁻¹.

[0131] To the above amic acid solution was added acetic anhydride (8.5mL, 9.0×10⁻² mols), triethylamine (1.26 mL, 9.0×10⁻³ mols) and sodiumacetate (0.88 g, 1.1×10⁻² mols). The resulting solution was refluxedlightly for 4 h under nitrogen. The reaction was allowed to cool to roomtemperature and bulk solvent was removed in vacuo. The resulting viscousliquid was resolvated in methylene chloride (200 mL) and extracted withdistilled water (3×200 mL). The organics were then dried over MgSO₄anhyd., filtered and solvent removed in vacuo to yield a light brownsolid (6.75 g, 76%). This material exhibited acceptable FT-IR and ¹H NMRspectral features.

Example H Preparation of “Bis(m-nitrobenzyl Carbamate) of DDI 1410”

[0132]

“Bis(m-nitrobenzyl Carbamate) of DDI 1410” (and Cyclic Isomers)

[0133] DDI 1410 (Henkel, “Dimer Diisocyanate”, 99.77 g, 1.65×10⁻¹ molsbased on 13.96% NCO), m-nitrobenzyl alcohol (50.8 g, 3.32×10⁻¹ mols) anddibutyltin dilaurate (0.5 mL, 8.3×10⁴ mols) were solvated in toluene(150 mL) in a 1 L four-necked flask equipped with mechanical stirrer,reflux condensor and internal temperature probe under nitrogen. Thereaction was heated to 85° C. for 2.5 h. FT-IR analysis of an aliquot ofthe reaction indicated complete comsumption of isocyanate functionalityas judged by the lack of a band at 2272 cm⁻¹. Solvent was removed fromthe reaction in vacuo to yield a yellow oil which solidified uponstanding at room temperature (152.4 g, 102% (trace toluene)). This solidexhibited satisfactory FT-IR and ¹H NMR spectral features.

Example I Preparation of “Bis(m-aminobenzyl carbamate) of DDI 1410”

[0134]

“Bis(m-aminobenzyl Carbamate) of DDI 1410” (and Cyclic Isomers)

[0135] The diamine product of Example H (39.6 g, 4.32×10⁻² mols) andstannous chloride dihydrate (97.55 g, 4.32×10⁻¹ mols) were slurried inethyl acetate (300 mL) in a 1 L three-necked flask equipped withmechanical stirrer and a reflux condenser under nitrogen. The reactionwas heated to light reflux and stirred vigorously for 3 h. The solutionwas allowed to cool to room temperature and brought to pH 7-8 with asolution of saturated sodium bicarbonate. The mixture was pushed througha 25 micron filter to yield a mixture which separated into a cloudyaqueous layer and a moderately clear organic layer. The aqueous layerwas isolated and washed with ethyl acetate (100 mL). The organic layerswere combined, washed with distilled water (300 mL) and dried overanhydrous MgSO₄. The slurry was filtered and solvent removed from thefiltrate in vacuo to yield yellow, sticky solid (33.8 g, 92%).

Example J Preparation of “Bis(m-maleimidobenzyl Carbamate) of DDI 1410”

[0136]

“Bis(m-maleimidobenzyl Carbamate) of DDI 1410” (and Cyclic Isomers)

[0137] Maleic anhydride (15.4 g, 1.57×10⁻² mols) was dissolved inacetone (300 mL) in a 2 L four-necked flask equipped with mechanicalstirrer, internal temperature probe and addition funnel under nitrogen.This solutionn was cooled to ˜4° C. on an ice bath. A solution of thediamine prepared in Example 1 (63.4 g, 7.48×10⁻² mols) in acetone (70mL) was charged to the addition funnel and added to the maleic anhydridesolution over a period of 30 minutes maintaining an internal temperatureof <10° C. The resulting solution was stirred for 1 h and subsequentlyallowed to warm to room temperature and stir for 2 h.

[0138] To this solution of amic acid was added acetic anhydride (24.7mL, 2.62×10⁻¹ mols), triethylamine (6.25 mL, 4.48×10⁻² mols) andmanganese acetate tetrahydrate (0.37 g, 1.50×10⁻³ mols). This solutionwas heated to light reflux for 6.5 h, then allowed to cool to roomtemperature. Bulk solvent was removed in vacuo, and the resulting darkliquid was dissolved in diethyl ether (500 mL). This solution was washedwith dist. H₂O (500 mL). The isolated organic layer was then washed withsaturated NaHCO₃ aq. (500 mL) and again with dist. H₂O (500 mL). Theorganics were isolated, dried over anhyd. MgSO₄, and solvent removed invacuo to yield a viscous orange oil. This material exhibited FT-IR, ¹HNMR and ¹³C NMR spectral features consistent with the expectedbismaleimide product.

What is claimed is:
 1. A curable package encapsulant compositioncomprising a maleimide compound and a curing initiator selected from thegroup consisting of a free-radical initiator, a photoinitiator, and acombination of those, the maleimide compound having the formula[M—X_(m)]_(n)—Q in which m is 0 or 1 and n is 1 to 6, and (a) M is amaleimide moiety having the structure:

in which R¹ is H or an alkyl group having 1 to 5 carbon atoms; (b) X isan aromatic group selected from the group of aromatic groups having thestructures:

(c) Q is a linear or branched chain alkyl, alkyloxy, alkyl amine, alkylsulfide, alkylene, alkyleneoxy, alkylene amine, alkylene sulfide, aryl,aryloxy, or aryl sulfide species, which may contain saturated orunsaturated cyclic or heterocyclic substituents pendant from the chainor as part of the chain, and in which any heteratom present may or maynot be directly attached to X.
 2. The composition according to claim 1in which Q is a linear or branched chain alkyl, alkyloxy, alkylene, oralkyleneoxy species, which may contain saturated or unsaturated cyclicor heterocyclic substituents pendant from the chain or as part of thechain.
 3. The composition according to claim 2 in which Q is a linear orbranched chain alkyl species, which may contain saturated or unsaturatedcyclic or heterocyclic substituents pendant from the chain or as part ofthe chain.
 4. The composition according to claim 1 in which Q is aurethane having the structure:

in which each R² independently is an alkyl, aryl, or arylalkyl grouphaving 1 to 18 carbon atoms; R³ is an alkyl or alkyloxy chain having upto 100 atoms in the chain, which chain may contain aryl substituents; Xis O, S, N, or P; and v is 0 to
 50. 5. The composition according toclaim 1 in which Q is an ester having the structure:

in which R³ is an alkyl or alkyloxy chain having up to 100 atoms in thechain, which chain may contain aryl substituents.
 6. The compositionaccording to claim 1 in which Q is an ester having the structure:

in which p is 1 to 100, and each R³ can independently be an alkyl oralkyloxy chain having up to 100 atoms in the chain, which chain maycontain aryl substituents; or each R³ can independently be a siloxanehaving the structure —(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)—SiR⁴ ₂—(CR¹ ₂)_(g)— inwhich the R¹ substituent independently for each position is H or analkyl group having 1 to 5 carbon atoms, the R⁴ substituent independentlyfor each position is an alkyl group having 1 to 5 carbon atoms or anaryl group, e and g are independently 1 to 10, and f is 1 to
 50. 7. Thecomposition according to claim 1 in which Q is an ester having thestructure:

in which p is 1 to 100, and each R³ can independently be an alkyl oralkyloxy chain having up to 100 atoms in the chain, which chain maycontain aryl substituents; or each R³ can independently be a siloxanehaving the structure —(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)—SiR⁴ ₂—(CR¹ ₂)_(g)— inwhich the R¹ substituent independently for each position is H or analkyl group having 1 to 5 carbon atoms, the R⁴ substituent independentlyfor each position is an alkyl group having 1 to 5 carbon atoms or anaryl group, e and g are independently 1 to 10, and f is 1 to
 50. 8. Acomposition comprising a maleimide compound and a curing initiatorselected from the group consisting of a free-radical initiator, aphotoinitiator, and a combination of those, the maleimide compoundhaving the formula [M—Z_(m)]_(n)—K in which m is 0 or 1 and n is 1-6,and (a) M is a maleimide moiety having the structure

in which R¹ is H or an alkyl having 1 to 5 carbon atoms; (b) K is anaromatic group selected from group of aromatic groups having thestructures:

in which p is 1 to 100;

in which p is 1 to 100;

in which R⁵, R⁶, and R⁷ are a linear or branched chain alkyl, alkyloxy,alkyl amine, alkyl sulfide, alkylene, alkyleneoxy, alkylene amine,alkylene sulfide, aryl, aryloxy, or aryl sulfide species, which maycontain saturated or unsaturated cyclic or heterocyclic substituentspendant from the chain or as part of the backbone in the chain, and inwhich any heteratom present may or may not be directly attached to thearomatic ring; or R⁵, R⁶, and R⁷ are a siloxane having the structure—(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)—SiR⁴ ₂—(CH₃)_(g)— in which the R¹substituent is H or an alkyl group having 1 to 5 carbon atoms and the R⁴substituent independently for each position is an alkyl group having 1to 5 carbon atoms or an aryl group, and e is 1 to 10 and f is 1 to 50;

(c) Z is a linear or branched chain alkyl, alkyloxy, alkyl amine, alkylsulfide, alkylene, alkyleneoxy, alkylene amine, alkylene sulfide, aryl,aryloxy, or aryl sulfide species, which may contain saturated orunsaturated cyclic or heterocyclic substituents pendant from the chainor as part of the chain, and in which any heteratom present may or maynot be directly attached to K.
 9. The composition according to claim 8in which Z is a linear or branched chain alkyl, alkyloxy, alkylene, oralkyleneoxy species, which may contain saturated or unsaturated cyclicor heterocyclic substituents pendant from the chain or as part of thechain.
 10. The composition according to claim 8 in which Z is a linearor branched chain alkyl species, which may contain saturated orunsaturated cyclic or heterocyclic substituents pendant from the chainor as part of the chain.
 11. The composition according to claim 8 inwhich Z is a urethane having the structure:

in which each R² independently is an alkyl, aryl, or arylalkyl grouphaving 1 to 18 carbon atoms; R³ is an alkyl or alkyloxy chain having upto 100 atoms in the chain, which chain may contain aryl substituents; Xis O, S, N, or P; and v is 0 to
 50. 12. The composition according toclaim 8 in which Z is an ester having the structure:

in which R³ is an alkyl or alkyloxy chain having up to 100 atoms in thechain, which chain may contain aryl substituents.
 13. The compositionaccording to claim 8 in which Z is an ester having the structure:

in which p is 1 to 100, and each R³ can independently be an alkyl oralkyloxy chain having up to 100 atoms in the chain, which chain maycontain aryl substituents; or each R³ can independently be a siloxanehaving the structure —(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)—SiR⁴ ₂—(CR¹ ₂)_(g)— inwhich the R¹ substituent independently for each position is H or analkyl group having 1 to 5 carbon atoms, the R⁴ substituent independentlyfor each position is an alkyl group having 1 to 5 carbon atoms or anaryl group, e and g are independently 1 to 10, and f is 1 to
 50. 14. Thecomposition according to claim 8 in which Z is an ester having thestructure:

in which p is 1 to 100, and each R³ can independently be an alkyl oralkyloxy chain having up to 100 atoms in the chain, which chain maycontain aryl substituents; or each R³ can independently be a siloxanehaving the structure —(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)—SiR⁴ ₂—(CR¹ ₂)_(g)— inwhich the R¹ substituent independently for each position is H or analkyl group having 1 to 5 carbon atoms, the R⁴ substituent independentlyfor each position is an alkyl group having 1 to 5 carbon atoms or anaryl group, e and g are independently 1 to 10, and f is 1 to
 50. 15. Thecomposition according to any one of claims 8 to 14 in which K is

in which p is 1 to
 100. 16. The composition according to any one ofclaims 8 to 14 in which K is

in which R⁵, R⁶, and R⁷ are a linear or branched chain alkyl, alkyloxy,alkyl amine, alkyl sulfide, alkylene, alkyleneoxy, alkylene amine,alkylene sulfide, aryl, aryloxy, or aryl sulfide species, which maycontain saturated or unsaturated cyclic or heterocyclic substituentspendant from the chain or as part of the chain, and in which anyheteroatom present may or may not be directly attached to the aromaticring.
 17. The composition according to any one of claims 8 to 14 inwhich K is


18. A composition comprising a vinyl compound and a curing initiatorselected from the group consisting of a free-radical initiator, aphotoinitiator, and a combination of those, the vinyl compound havingthe formula

in which m is 0 or and n is 1-6; and (a) R¹ and R² are H or an alkylgroup having 1 to 5 carbon atoms, or together form a 5 to 9 memberedring with the carbons forming the vinyl group; (b) B is C, S, N, O,C(O), C(O)NH or C(O)N(R⁸), in which R⁸ is an alkyl group having 1 to 5carbon atoms; (c) X is an aromatic group selected from the group ofaromatic groups having the structures:

(d) Q is a linear or branched chain alkyl, alkyloxy, alkyl amine, alkylsulfide, alkylene, alkyleneoxy, alkylene amine, alkylene sulfide, aryl,aryloxy, or aryl sulfide species, which may contain saturated orunsaturated cyclic or heterocyclic substituents pendant from the chainor as part of the chain, and in which any heteratom present may or maynot be directly attached to X.
 19. The composition according to claim 18in which Q is a linear or branched chain alkyl, alkyloxy, alkylene, oralkyleneoxy species, which may contain saturated or unsaturated cyclicor heterocyclic substituents pendant from the chain or as part of thechain.
 20. The composition according to claim 19 in which Q is a linearor branched chain alkyl species, which may contain saturated orunsaturated cyclic or heterocyclic substituents pendant from the chainor as part of the chain.
 21. The composition according to claim 18 inwhich Q is a urethane having the structure:

in which each R² independently is an alkyl, aryl, or arylalkyl grouphaving 1 to 18 carbon atoms; R³ is an alkyl or alkyloxy chain having upto 100 atoms in the chain, which chain may contain aryl substituents; Xis O, S, N, or P; and v is 0 to
 50. 22. The composition according toclaim 18 in which Q is an ester having the structure:

in which R³ is an alkyl or alkyloxy chain having up to 100 atoms in thechain, which chain may contain aryl substituents.
 23. The compositionaccording to claim 18 in which Q is an ester having the structure:

in which p is 1 to 100, and each R³ can independently be an alkyl oralkyloxy chain having up to 100 atoms in the chain, which chain maycontain aryl substituents; or each R³ can independently be a siloxanehaving the structure —(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)—SiR⁴ ₂—(CR¹ ₂)_(g)— inwhich the R¹ substituent independently for each position is H or analkyl group having 1 to 5 carbon atoms, the R⁴ substituent independentlyfor each position is an alkyl group having 1 to 5 carbon atoms or anaryl group, e and g are independently 1 to 10, and f is 1 to
 50. 24. Thecomposition according to claim 18 in which Q is an ester having thestructure:

in which p is 1 to 100, and each R³ can independently be an alkyl oralkyloxy chain having up to 100 atoms in the chain, which chain maycontain aryl substituents; or each R³ can independently be a siloxanehaving the structure —(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)SiR⁴ ₂—(CR¹ ₂)_(g)— inwhich the R¹ substituent independently for each position is H or analkyl group having 1 to 5 carbon atoms, the R⁴ substituent independentlyfor each position is an alkyl group having 1 to 5 carbon atoms or anaryl group, e and g are independently 1 to 10, and f is 1 to
 50. 25. Acomposition comprising a vinyl compound and a curing initiator selectedfrom the group consisting of a free-radical initiator, a photoinitiator,and a combination of those, the vinyl compound having the formula

in which m is 0 or 1 and n is 1-6; and (a) R¹ and R² are H or an alkylgroup having 1 to 5 carbon atoms, or together form a 5 to 9 memberedring with the carbons forming the vinyl group; (b) B is C, S, N, O,C(O), C(O)NH or C(O)N(R⁸), in which R⁸ is an alkyl group having 1 to 5carbon atoms; (c) K is an aromatic group selected from the group ofaromatic groups having the structures:

in which p is 1 to 100;

in which p is 1 to 100;

in which R⁵, R⁶, and R⁷ are a linear or branched chain alkyl, alkyloxy,alkyl amine, alkyl sulfide, alkylene, alkyleneoxy, alkylene amine,alkylene sulfide, aryl, aryloxy, or aryl sulfide species, which maycontain saturated or unsaturated cyclic or heterocyclic substituentspendant from the chain or as part of the backbone in the chain, and inwhich any heteratom present may or may not be directly attached to thearomatic ring; or R⁵, R⁶, and R⁷ are a siloxane having the structure—(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)—SiR⁴ ₂—(CH₃)_(g)— in which the R¹substituent is H or an alkyl group having 1 to 5 carbon atoms and the R⁴substituent independently for each position is an alkyl group having Ito 5 carbon atoms or an aryl group, and e is 1 to 10 and f is 1 to 50;

(d) Z is a linear or branched chain alkyl, alkyloxy, alkyl amine, alkylsulfide, alkylene, alkyleneoxy, alkylene amine, alkylene sulfide, aryl,aryloxy, or aryl sulfide species, which may contain saturated orunsaturated cyclic or heterocyclic substituents pendant from the chainor as part of the chain, and in which any heteratom present may or maynot be directly attached to X.
 26. The composition according to claim 25in which Z is a linear or branched chain alkyl, alkyloxy, alkylene, oralkyleneoxy species, which may contain saturated or unsaturated cyclicor heterocyclic substituents pendant from the chain or as part of thechain.
 27. The composition according to claim 25 in which Z is a linearor branched chain alkyl species, which may contain saturated orunsaturated cyclic or heterocyclic substituents pendant from the chainor as part of the chain.
 28. The composition according to claim 25 inwhich Z is a urethane having the structure:

in which each R² independently is an alkyl, aryl, or arylalkyl grouphaving 1 to 18 carbon atoms; R³ is an alkyl or alkyloxy chain having upto 100 atoms in the chain, which chain may contain aryl substituents; Xis O, S, N, or P; and v is 0 to
 50. 29. The composition according toclaim 25 in which Z is an ester having the structure:

in which R³ is an alkyl or alkyloxy chain having up to 100 atoms in thechain, which chain may contain aryl substituents.
 30. The compositionaccording to claim 25 in which Z is an ester having the structure:

in which p is 1 to 100, and each R³ can independently be an alkyl oralkyloxy chain having up to 100 atoms in the chain, which chain maycontain aryl substituents; or each R³ can independently be a siloxanehaving the structure —(CR¹ ₂)_(e)—[SiR⁴ ₂O]_(f)—SiR⁴ ₂—(CR¹ ₂)_(g)— inwhich the R¹ substituent independently for each position is H or analkyl group having 1 to 5 carbon atoms, the R⁴ substituent independentlyfor each position is an alkyl group having 1 to 5 carbon atoms or anaryl group, e and g are independently 1 to 10, and f is 1 to
 50. 31. Thecomposition according to claim 25 in which Z is an ester having thestructure:

in which p is 1 to 100, and each R³ can independently be an alkyl oralkyloxy chain having up to 100 atoms in the chain, which chain maycontain aryl substituents; or each R³ can independently be a siloxanehaving the structure —(CR¹ ₂)_(e)—[SiR⁴ ₂—O]_(f)—SiR⁴ ₂—(CR¹ ₂)_(g)— inwhich the R¹ substituent independently for each position is H or analkyl group having 1 to 5 carbon atoms, the R⁴ substituent independentlyfor each position is an alkyl group having 1 to 5 carbon atoms or anaryl group, e and g are independently 1 to 10, and f is 1 to
 50. 32. Thecomposition according to any one of claims 25 to 31 in which K is

when p is 1 to
 100. 33. The composition according to any one of claims25 to 31 in which K is

in which R⁵, R⁶, and R⁷ are a linear or branched chain alkyl, alkyloxy,alkyl amine, alkyl sulfide, alkylene, alkyleneoxy, alkylene amine,alkylene sulfide, aryl, aryloxy, or aryl sulfide species, which maycontain saturated or unsaturated cyclic or heterocyclic substituentspendant from the chain or as part of the chain, and in which anyheteroatom present may or may not be directly attached to the aromaticring.
 34. The composition according to any one of claims 25 to 31 inwhich K is


35. A composition comprising a maleimide compound as described in anyone of claims 1 to 17 and a vinyl compound as described in any one ofclaims 18 to 34 , and a curing initiator.
 36. A composition comprising amaleimide compound as described in any one of claims 1 to 17 , or avinyl compound as described in any one of claims 18 to 34 , or acombination of a maleimide compound as described in any one of claims 1to 17 and a vinyl compound as described in any one of claims 18 to 34 ,and an anionic or cationic curing initiator.
 37. An electronic assemblycomprising an electronic component encapsulated with a cured adhesivecomposition prepared from a composition according to any one of thepreceding claims.